Telephone calls to 911 are generally routed to a public safety answering point (PSAP). The public safety answering point (PSAP) is a center with 911 operators (or agents) who coordinate emergency services to respond to 911 calls. Generally, when a person places a 911 call, the call is routed through a central office (CO) through a tandem to the public safety answering point (PSAP). An agent at the public safety answering point (PSAP) answers the call and provides whatever assistance is required to handle the emergency.
Many communities provide enhanced 911 (E911) emergency telephone calling services. With E911, emergency operators receive the location of 911 calls as well as the telephone number from which the call originated. Location information is obtained from an Automation Location Information (ALI) database. Telephone subscriber information (e.g., name, address, telephone number) is typically used to build the ALI database. For organizations using a private branch exchange (PBX) telephone switch, however, subscriber information may be limited to the organization's name and its main address. As a result, the “address” displayed to emergency operators who receive a 911 call from inside a PBX can be imprecise or even far away from the caller's actual location. In this case, the operator must obtain location information from the caller defeating a benefit of E911 services. E911 emergency service calls from Voice Over Internet Protocol (VoIP) telephones is discussed, for example, in U.S. Pat. No. 6,665,611, the disclosure of which is hereby incorporated herein in its entirety by reference.
In addition, systems for dialing an emergency telephone number from a teleworking client remotely coupled to a PBX are discussed in U.S. Pat. No. 6,678,356, the disclosure of which is hereby incorporated herein in its entirety by reference. More particularly, systems for dialing an emergency telephone number from a teleworking client detect at a teleworking client when an emergency number is dialed, disconnect the teleworking client from the PBX/MLTS, connect the teleworking client to the public switched telephone network (PSTN), and dial an associated stored number. While discussed with respect to a teleworking client, aspects of the '356 patent may also be applied to other dialup network connections.